nodejs mysql multiple where query's

I've been working with mysql in nodejs for a bit and I can't seem to figure out how to use the query with multiple where statements. Like:

SELECT * FROM user_information WHERE a=a or b=b

Right now i have this as my code:

    connection.query("SELECT * FROM user_information WHERE username=" + registerarray[1] + " OR email=" + registerarray[3],function(err, results){
            if (err){console.error(err);}
    });

Thank you and best regards

Me

via Axel D'Olislager